Apparatus for handling protectors for elongate objects

ABSTRACT

An apparatus is proposed for applying and removing protective caps (1) to and from the ends of elongate members (6). The protective cap (1) has a hard base portion (5) and a cover portion (2) of flexible, resilient material, extending from the base portion (5) and operative to cover a portion of an outer surface of the elongate member (6). The apparatus comprises: a gripping mechanism (44) operative to grip the hard base portion (5) of the protective cap (1); a drive mechanism, connected to the gripping mechanism (44), operative to move the protective cap (1) to and from the end of the elongate member (6); and a tool operative to perform at least one of the operations of (i) unfurling the cover portion to secure it to the outer surface of the elongate member, (ii) furling the cover portion to detach it from the outer surface of the elongate member.

FIELD OF INVENTION

The present invention relates to an apparatus for moving protectors to and from the ends of elongate members. In particular, wherein the apparatus is a robotic arm and the protectors are caps for the end of pipes, such as those used in drilling operations.

BACKGROUND OF THE INVENTION

It is important for pipes used in drilling operations to be highly reliable; faults within a string of pipes can cause serious problems, both for the mechanical operation of the machinery (with related financial costs) and for the environment. Accordingly, it is essential to protect pipes during storage and transportation of the pipes. Wear generated in storage or transit is particularly undesirable as it decreases the lifetime of the pipe.

The end portions of an oil pipe are often termed the “box end” and “pin end”, and are female and male connecting end portions respectively. The box and pin ends of pipes often comprise helical threads to interlink and secure neighbouring pipes to one another. The thread of the box end is provided on an inwardly-facing surface, and the thread of the pin end is provided on an outwardly-facing surface. Avoiding wear to the threads of the pipes is of particular importance, as the connections between the pipes are the most vulnerable portion of a string of pipes.

Protectors for pipes are well known, and are usually caps formed of metal or strong plastic that are designed to be screwed onto/into the threaded sections of the pin/box end of the pipe. A problem with this is that different pipes have different dimensions, and not all threads are identical. Accordingly, someone intending to protect a pipe would have to acquire a specific protector for a specific pipe diameter and thread configuration. This creates additional logistic and financial burdens on the user of pipes for drilling operations. The financial burden is further compounded by the fact that the specific threads are usually licensed, and therefore the cost of a specific protector may be high.

A further problem with threaded protectors is that it takes significant time to apply the protector to the pipe, and subsequently to remove it. Furthermore, as the pipes are often large in diameter, a large force is required to rotate the protector and thread it onto or off the pipe. Accordingly, injuries to a user's shoulders and arms are common.

As disclosed in GB1909268.3, which was not in the public domain at the priority date of the present application, protective caps have been proposed to solve these problems. These protective caps have a hard base portion and a cover portion of flexible resilient material extending out of the base portion, operative when in an un-gathered configuration to cover a portion of an outer surface of an elongate member. These caps are designed to be manually operated with greater ease (e.g. can be applied/removed faster) than conventional caps.

On drilling platforms, the drilling pipes are typically located in a ‘red zone’ within which operation dangerous to personnel are performed. To avoid injuries, all operations and machines in the red zone must be stopped when personnel are to enter it. The protective caps reduce the amount of time personnel are required to be in the red zone to protect the ends of the pipes.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new and useful apparatus for applying and removing protective caps to and from the ends of elongate members.

In general terms, a first aspect of the invention proposes an apparatus for applying and removing protective caps to and from the ends of elongate members, the protective cap having a hard base portion and a cover portion of flexible, resilient material, extending from the base portion and operative to cover a portion of an outer surface of the elongate member, the apparatus comprising:

-   -   a gripping mechanism operative to grip the hard base portion of         the protective cap;     -   a drive mechanism, connected to the gripping mechanism,         operative to move the protective cap to and from the end of the         elongate member; and     -   a tool operative to perform at least one of the operations         of (i) unfurling the cover portion to secure it to the outer         surface of the elongate member, (ii) furling the cover portion         to detach it from the outer surface of the elongate member.

The apparatus makes it possible for the protective cap to be applied to and/or removed from the end of the cap substantially without human involvement (except optionally in order to initiate the operation(s), and this may be performed remotely).

This may provide any of several advantages. First, the time taken in the operation(s) may be reduced compared to their performance by a human. Secondly, the accuracy of performing the operation(s) may be improved. Thirdly, since the human effort is reduced, the cost (e.g. as measured in man-hours) of the operation(s) may be reduced. In particular, using the apparatus the operation(s) may be performed in a region in which other operations are performed which are potentially dangerous to humans (such as a red zone) without a human entering it, and therefore with improved safety and/or without downtime to the other operation(s) being performed in that location.

The tool may be adapted to perform one or more of the operations of (i) unfurling the cover portion to secure it to the outer surface of the elongate member and (ii) furling the cover portion to detach it from the outer surface of the elongate member.

In an embodiment, the apparatus may further comprise a control unit adapted to transmit control instructions to one or more of the gripping mechanism, the drive mechanism, and the tool. The control instructions may cause the gripping mechanism, drive mechanism, and/or tool to perform one or more operations. For example, the control unit may transmit a first control instruction which causes the tool to unfurl the cover portion of the protective cap, and may transmit a second control instruction which causes the tool to furl the cover of the protective cap.

Another expression of the invention is a method of applying a protective cap an elongate object and/or removing a protective cap from an elongate object by the operation of the apparatus described herein.

Another expression of the invention is a combination of the apparatus with one or more protective caps of the types described herein.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will now be described for the sake of example only with reference to the following drawings in which:

FIG. 1 is a cross-sectional diagram showing a protective cap covering the male connecting end of a drill pipe.

FIGS. 2A-2B are cross-sectional diagrams showing a protective cap with an alternate ‘vacuum’ cover portion.

FIGS. 3A-3B are cross-sectional diagrams showing a protective cap with an alternate elastic band cover portion.

FIG. 4 is a view of an apparatus which is an embodiment of the invention, situated in the red zone of a drilling platform

FIGS. 5A-5C are views of a gripping mechanism of a first embodiment of the apparatus, as the gripping mechanism engages with a base portion of the protective cap.

FIGS. 6A-6B are views of a gripping mechanism of a second embodiment of the apparatus, as the gripping mechanism engages with a base portion of the protective cap.

FIG. 7 is a side view of an embodiment of the apparatus in which a tool of the apparatus is realized as a clamp.

FIG. 8 is a side view of an embodiment of the apparatus in which a tool of the apparatus is realized as a rolling belt.

FIGS. 9A-9B are views of sensing means of an embodiment of the apparatus.

FIGS. 10A-10C are side views of the operation of the rolling belt tool in an embodiment of the apparatus.

FIGS. 11A-11C are side views of the operation of the clamp tool in an embodiment of the apparatus.

FIGS. 12A-12F are views of the operation of an embodiment of the apparatus.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to describe the operation of the apparatus for applying and removing protective caps to and from the ends of elongate members, exemplary protective caps are first described.

Referring to FIG. 1, a protective cap 1 is shown comprising a sheath of flexible, resilient material 2 and a rigid base portion 5. The rigid base portion 5 has a tubular wall 5 b upstanding from an end section (end wall) 9. The tubular wall 5 b has a free edge 9 c furthermost from the end section 9 of the base portion 5. The protective cap 1 covers a male connecting end of a drill pipe 6 with an outwardly facing threaded section 6 a. That is, the protective cap 1 is shown in a gripping configuration, gripping the pipe 6. The protective cap 1 is circularly symmetric about a central axis 1 a which is coincident with a central axis of the pipe 6.

The base portion 5 is formed of a rigid material and defines a cavity. The base portion 5 therefore also covers the threaded section 6 a of the pipe 6, and, as noted, is of a rigid material so as to protect the vulnerable outwardly facing threads 6 a from deformation which may occur during the transport or storage of the drill pipe 6.

The sheath 2 is composed of two portions: an insert portion 4 inserted into the cavity in the base portion 5, and a cover portion 3 which is not inserted into the base portion 5. In this embodiment, the sheath 2 is a single tubular member, and the insert portion 4 and cover portion 3 are respective tubular portions of this tubular member. The insert portion 4 may be attached to the base portion 5 by adhesive and/or be maintained there by frictional contact with the inwardly-facing surface of the base portion. The cover portion 3 is supported from the inwardly facing surface of the base portion 5, via the insert portion 4. In the gripping configuration the cover portion 3 extends away from the free edge 9 c of the base portion towards a free edge 9 d of the cover portion 3. The inner surface 7 of the insert portion 4 is designed to cover the outwardly facing threaded section 6 a of the pipe 6. As shown in the figure, the insert portion 4 may have one or more ridges 8 on its inner surface 7. The cover portion 3 is operative to grip the threaded portion 6 a of the outer surface of the pipe 6. The sheath of this second embodiment contains an end wall 9 a which lies against the end section (end wall) 9 of the rigid base portion 5.

The male connecting portion of a drill pipe 6 is termed the ‘pin end’ of the pipe. The threaded section 6 a of a pin end of a drill pipe is often tapered, as can be seen in FIG. 1. The insert portion 4 of a protective cap 1 for drill pipes is tapered accordingly, as shown in FIG. 1. However, it will be appreciated that the end of an elongate member may not be tapered, as is the case for example for casing pipes; the insert portion of a protective cap for a casing pipe would not taper accordingly. It is to be understood that the embodiments described above are applicable to protective caps for drill pipe ends of any type, and indeed to provide/remove protective caps for any elongate object.

The cover portion 3 is a laminar (i.e. sheet-like e.g. of substantially uniform thickness transverse to its major surfaces; but not flat) portion which can be “furled”, that is collected (e.g. rolled up) into a non-gripping, e.g. gathered, configuration before application of the cap 1 onto the end of the drill pipe 6. When the end of the pipe 6 is inserted into the insert portion 4, the gathered cover portion 4 can be unfurled (e.g. unrolled) in order to grip and secure the cap 1 onto the pipe 6. The cover portion 3 is shown in this figure in the unfurled, gripping configuration.

As noted, the insert portion 4 has an inner surface 7 from which optionally ridges 8 may extend inwardly. These ridges 8 may be circular about the axis of the pipe, and they may either be spaced apart, as shown in the diagram, or they may be adjacent to each other. The ridges 8 are also optionally provided with a lubricant which covers the threaded section 6 a of the pipe 6.

The cover portion 3 can be manipulated into a non-gripping configuration by gathering it (e.g.

rolling it, into a roll having a spiral cross-section) away from the surface of the pipe 6. In the non-gripping configuration it applies no force, or a much reduced force, to the surface of the pipe 6.

For example, the cover portion 3 may be positioned in a roll over the exterior surface of the tubular wall 5 b. Alternatively, the cover portion 3 may be positioned on the exterior surface of the tubular wall 5 b in an un-rolled configuration, such that it projects back from the free edge 9 c in the direction towards the end section 9 of the base portion 5. In either case, the cover portion 3 may be maintained in the non-gripping configuration by its own resilience. To make this more likely, the base portion 5 may have a generally decreasing cross-section (transverse to the axis 1 a of the pipe 6) in the axial direction which is from the free edge 9 c towards the end section 9 of the base portion 5 (i.e. the direction into the cavity).

The cover portion of the protective cap 1 may include one or more retraction portions (not shown), such as ears of material extending from their cover portion. The retraction portion is designed to assist the user in removing the cap from the male connecting end of the elongate member by providing a portion that is easier to grasp than the cover portion of the cap.

Other possible forms of the cover portion of the cap are now described. FIGS. 2A and 2B show a cross section of a first example of an alternative cover portion which is rotationally symmetric about an axis (in use, the axis of the elongate member). The cover portion 20 has a lip 25. The lip may be reliantly urged against the outer surface of the elongate member 26, as shown in FIG. 2A, preferably so as to provide an airtight seal encircling the elongate member 26. The protective cap may be attached to/removed from the elongate member by any of the embodiments of the apparatus described below.

Also present in the base portion 23 of the protective cap is an airtight valve 21. As shown in the figure, this valve 21 may be located on the tubular wall of the base portion 23. The apparatus may be operative to pump out through this valve 21 the air between the protective cap and the elongate member 26, thereby creating a vacuum in a volume 22 within the cap, manipulating (deforming) the cover portion and securing the cap to the elongate member with the vacuum pressure, as shown in FIG. 2B.

The apparatus may further be operative to open the valve 21 in order to release this pressure and to allow the protective cap to be removed from the end of the elongate member 26. The insert portion 24 may be operative to at least cover the end section of the base portion of the protective cap and to act as a seal. It will be appreciated that the cover portion 20 may be configured such that the cap is secured by the vacuum pressure alone; alternatively this configuration may be used in conjunction with a cover portion which adequately grips the outer surface of the elongate member without the vacuum (i.e. the vacuum may optionally be used to more securely hold the cap to the elongate member).

FIGS. 3A and 3B show a cross section of a second example of an alternative cover portion. Again, this protective cap is circularly symmetric about an axis which in use is typically a longitudinal axis of the elongate member. The cover portion comprises a band of resilient (elastic) material 30 attached to the protective cap by a connector portion 31 which is contiguous with an insert portion 34 of the sheath. As shown in FIG. 3A, the band 30 sits in a groove 32 formed on the outer surface of the base portion 33 when the cover portion is in the non-gripping configuration. Thus, in the non-gripping configuration, the band 30 is secured in the groove 32 of the base portion 33 by its own radial elastic force. FIG. 3B shows the cover portion once it has been manipulated (unfurled) into the gripping configuration. As shown in FIG. 3B, when the cover portion has been manipulated into the gripping configuration, the elastic band 30 of the cover portion has been removed from the groove 32 and encircles the elongate member 36 and exerts the radial elastic force against the elongate member 36, securing the protective cap to the elongate member. The band 30 may be formed of a less elastic material than the connecter 31, or it may be the same material. In the case that it is the same material the high elastic force provided by the band 30 is therefore due to its cross-sectional area or the way in which it was formed. In either case, the cover portion 31 has a higher elasticity per unit length at the band 30 (i.e. at a position further spaced from the base portion 33 in the gripping configuration) than where it meets the edge of the base portion 33.

The protective caps described above do not have a threaded section which matches a threaded section which the elongate member may have. The protective caps are held in place on the surface of the elongate member by friction. Thus, a cap which has a certain diameter is able to be attached to any elongate member within a range of diameters. For example, drill pipes tend to have an outer diameter (O.D.) in the range of 2″ to 8.5″. This range may be adequately covered by about four caps of different respective sizes. This reduces the required number of protectors to protect the range of pipes that will be used in drilling operations, such as mining or oil and gas drilling and exploration operations.

Many variations are possible to the cap handled by the apparatus of the invention, as will be clear to a skilled reader. For example, the outer profile of the rigid base portion may have a profile, looking along the central axis, which is not circular. It may, for example, appear as generally square, e.g. with rounded corners. The insert portion in this case also is preferably formed so that the insert portion has a shape which conforms to, and in use lies against, the inwardly-facing surface of the rigid base portion.

Turning now to the apparatus itself, FIG. 4 shows an example of the apparatus 40 located on the drill floor 41. The drill floor 41 has a red zone demarcated by red zone line 42. The drill pipe 43 (elongate member) is located within this red zone. As the apparatus 40 can be automatically or remotely operated, this reduces the time during which the machinery in the red zone must be stopped, saving the operators of oil rigs significant time and, therefore, money. As can be seen in the figure, the apparatus 40 has a gripping mechanism 44 operative to grip the hard base portion of the protective cap. The gripping mechanism 44 is connected to a drive mechanism 45, which may be, for example, a mechanical arm. As will be discussed later, a mechanical arm is not the only example of a drive mechanism 45. Several forms of the mechanical arm are possible. For example the arm may be a robotic arm (i.e. controlled automatically—i.e.

substantially without human involvement save optionally for initiation) or the arm may be controlled remotely by a human operator. Alternatively, the drive mechanism could comprise an elevation and/or translation drive unit which does not comprise an elongate arm member, but which raises the gripping mechanism 44 of the apparatus 40 to the end of the drill pipe. The apparatus 40 also comprises at least one tool 46 operative to manipulate (i.e. furl or unfurl) the cover portion of the protective cap to secure it to or detach it from the drill pipe 43 (or other elongate member). The tool 46 is adapted to manipulate the cover portion of the protective cap.

Where the drive mechanism 45 is controlled automatically (e.g. a robotic arm), the apparatus 40 may further comprise a control unit operative to transmit control instructions to the gripping mechanism 44, drive mechanism 45, and/or tool 46. The control instructions may cause the gripping mechanism 44, drive mechanism 45, and/or tool 46 to perform one or more operations. For example, the control unit may transmit a first control instruction which causes the tool 46 to unfurl the cover portion of the protective cap to detach it from the pipe 43, and may transmit a second control instruction which causes the tool 46 to furl the cover of the protective cap to secure it to the pipe 43.

Turning to FIGS. 5A to 5C, a first possible form of the gripping mechanism 44 of the embodiment will be described. FIG. 5A shows a zoomed-in view of the first form of the gripping mechanism 44 in a disengaged state. The gripping mechanism comprises a plurality of crescent shaped gripping members 51 connected to a base platform 52 which is for contacting the end wall (see for example FIG. 1, reference numeral 9) of the base portion 50. The crescent gripping members 51 radially converge to slot into a recess or groove 50 a of the base portion 50 (i.e. the base portion 50 has a female portion which engages with a male portion of the gripping mechanism).

FIG. 5B shows the gripping mechanism in an engaged state, with the crescent gripping members 51 gripping the hard base portion 50. FIG. 5C is a cross sectional view of a gripping member 51 (in particular a male portion 51 b of the gripping member 51) engaged in the recess 50 a of the base portion 50. Also visible are insert portion 53 and ridges 54 of the protective cap.

It will be appreciated, in particular from FIG. 5C, that either the base portion or the gripping mechanism may have a male portion or a female portion, or they may both have both female and male portions. For example, it could be said that 50 b, which is the end of the base portion 50 b adjacent to the recess 50 a, is a male portion which engages with a female portion 51 a (i.e. a recess) of the crescent gripping member 51.

In this gripping mechanism embodiment, there are 3 crescent gripping members 51, but it will be appreciated that the number may be 2 or greater. The three crescents 51 may converge and engage with the groove 50 a of the base portion 50 in a groove assisting both in centering and holding the protector engaged with the base platform 52. The three crescents 51 are preferably driven from one actuator with a combined motion through tooth-belts, bars, or another type of transmission within the gripping mechanism. Thus, all three crescents 51 will always have the same orientation as each other, except for being mutually angularly displaced by 120 degrees about the axis of the elongate member.

Moving onto FIG. 6A and 6B, a second possible form of the gripping mechanism of the embodiment will now be described. The gripping mechanism comprises a plurality of gripping pins 61 arranged to converge into the recess 60 a of the base portion 60, and a base platform 62 which is for contacting the end wall of the base portion 60. FIG. 6A shows the gripping mechanism in a disengaged state, and FIG. 6B shows the gripping mechanism in an engaged state, with the gripping pins 61 converged to slot into the recess 60 a and thus gripping the base portion 60. Optionally, the base portion may comprise respective recesses for receiving the pins 61, and guide surfaces for guiding the pins into the recesses, e.g. including rotating the base portion 60 about its axis until the pins are in register with the respective recesses. As with the previous embodiment, any suitable number of gripping pins 61 may be provided, and they are all preferably driven by the same actuator.

It will be appreciated that the gripping mechanism may take other forms, such as being a mechanism with no base platform 52,62, or in which the gripping member is a single collapsible ring which radially converges to grip the hard base portion 50.

As the gripping mechanism is operative to align with the cap, it can be seen that the central axis of the cap (see 1 a from FIG. 1) will align with the convergent point of the gripping members of the gripping mechanism. The convergent point of the gripping members can therefore also be seen to be the origin of a central axis of the gripping mechanism (e.g. the centre of base platform 52, 62). Additionally, since the gripping mechanism radially converges, the apparatus is capable of gripping protective caps with a wide range of outer diameters.

Attention will now be turned to possible forms of the tool of an embodiment of the apparatus. The tools of an embodiment may be attached to (mounted on) the base platform of the gripping mechanism, however it will be appreciated that the tool could be attached to any part of the apparatus, e.g. the drive mechanism. The tools of the below described embodiments comprise an engaging member and tool-arms to move the engaging member to and from the cover portion of the protective cap. The engaging member may be adapted to engage the cover portion of the protective cap. The tool-arms are capable of moving the engaging member along the required path (e.g. which may depend upon any tapering of the end of the elongate member) and to the required distance (i.e. so as to fully unfurl the cover portion). Further, the tool-arms must be extendable so as to be able to place and remove the protective cap onto/from the tool. The apparatus may additionally comprise a mechanism (not shown) for withdrawing air through a valve, in the case that the apparatus is designed to move protective caps of the embodiment described in FIGS. 2A and 2B.

FIG. 7 shows an embodiment of the apparatus including three instances of a first form of the tool 72. The base portion 70 is gripped by the gripping mechanism of the apparatus and the cover portion 71 is in the gripping configuration, although the elongate member has been omitted from this figure for simplicity. Each tool comprises a clamp 72 (engaging member) attached to the base platform by tool-arms 73. The tool-arms 73 move the clamp 72 with respect to the base platform and the cap, and the clamp 72 engages with a retraction portion 71 a of the cover portion 71. The operation of the tool will be described in greater detail later, however it will be appreciated that the retraction portion 71 a is preferable but not essential for the clamp 72 to engage with the cover portion 71. The clamp 72 may be adapted to engage the cover portion 71. As the cover portion 71 is formed of a flexible resilient material it is possible for the clamp 72 to pinch and engage the cover portion 71, with or without a retraction portion 71 a. In the embodiment shown there are three sets of clamps 72 and tool-arms 73, arranged equilaterally around the gripping mechanism (i.e. in use about the axis of the elongate member), but it will be appreciated that the tool may comprise any number of clamps 72 and arms 73 and that, for example, a single tool-arm 73 may be connected to a plurality of clamps 72. Further, it is not essential that the tool-arms 73 are spaced around the gripping mechanism equally. The tool-arms 73 may be driven by a single actuator and move in synchronization, or alternatively they may operate independently. The tool-arms 73 may move in response to receiving a control instruction from a control unit of the apparatus.

FIG. 8 shows an embodiment of the apparatus including three instances of a second form of the tool. As with FIG. 7, the base portion 80 is gripped by the gripping mechanism of the apparatus and the cover portion 81 is in the gripping configuration, with the elongate member omitted for simplicity. Each tool comprises an endless rolling belt 82 (engaging member) connected to the gripping mechanism with tool-arms 83. The rolling belt 82 surrounds a plurality of rotating mechanisms (rollers). The endless belt 82 is operative to engage the cover portion 81, and the rotating mechanisms are operative to rotate the belt, to furl or unfurl the cover portion 81 through friction. The endless belt 82 may be adapted to engage the cover portion 81. It will be appreciated that in other embodiments the engaging member of the tool may not comprise a belt 82, such that the rotating mechanism engage the cover portion 81 directly. Furthermore, each tool may comprise only a single rotating mechanism.

In the forms of the tool with at least one rotating mechanism, e.g. with a rolling belt 82, the presence of a retraction portion 81 a on the cover portion 81 is less beneficial compared to the tool embodiments with a clamp 72. However, the curve of the retraction portion 81 a, as shown in the figure, may still assist the tool by providing a greater surface area to contact the belt 82 (if present) or the rotating mechanisms of the tool.

The embodiment of FIG. 8 comprises of three tools (i.e. three sets of rolling belts 82 and tool-arms 83), arranged equilaterally around the gripping mechanism (i.e. in use about the axis of the elongate member), but it will be appreciated that the tool may comprise any number of rolling belts 82 and arms 83 and that, for example, a single tool-arm 83 may be connected to a plurality of rolling belts 82. Further, it is not essential that the tool-arms 83 are spaced around the gripping mechanism equally. The tool-arms 83 may be driven by a single actuator and move in synchronization, or alternatively they may operate independently. The tool-arms 83 may move in response to receiving a control instruction from a control unit of the apparatus.

Both forms of the tools shown in FIGS. 7 and 8 may be improved by the addition of cameras, or other sensing means, which can detect the proximity of the tool to the cover portion of the cap and/or to the elongate member. Sensing means may also be provided to detect the proximity of the gripping mechanism to the hard base portion of the cap. Where the apparatus is provided with a control unit, the proximity detection result may be transmitted from the sensing means to the control unit. The proximity detection result may be used to generate or modify control instructions transmitted to the apparatus by the control unit. Two embodiments of sensing means are exemplified in FIGS. 9A and 9B.

FIG. 9A shows an embodiment of the apparatus with a rolling belt 92 a tool, which has been modified with the addition of a proximity sensor 93 a operative to detect the distance from the rolling belt 92 a to the elongate member (drill pipe) 94. The proximity sensor 93 a may be used to assist the apparatus in properly aligning the tool (and hence the cap) with the pipe when mounting the pipe to the cap, as shown in FIG. 9A which shows the cover portion 91 in a gathered configuration, ready to be unfurled by the rolling belt 92 a onto the elongate member 94. Additionally the sensor 93 a may be used to assist in aligning the apparatus with the cap when dismounting the cap from the pipe, i.e. for aligning the gripping mechanism with the base portion of the cap, and also for aligning the rolling belt 92 a with the cover portion 91. The proximity sensor 93 a can further be used to generate a distance feedback, during the operation (i.e. spinning) of the tool-belt 92 a; this feedback can be used to detect (e.g. if the distance to the pipe deviates from an expected value) and thus correct an error in the operation of the tool. For example, the feedback may be used to modify control instructions transmitted to the tool by a control unit.

FIG. 9B shows a further example of a sensing means specific to the clamp embodiment of the tool. In this embodiment the tool is provided with a proximity sensor 93 b operative to detect the distance from the clamp 92 b to the cover portion 91, specifically the retraction portion 91 a. This proximity sensor allows the apparatus (if automated) or a human operator to detect whether or not the cover portion 91 or retraction portion 91 a are located within the clamp 92 b. During operation of the clamp 92 b, the proximity sensor 91 a can be used to determine a successful grip and hold of the cover portion 91 or retraction portion 91 a throughout the operation of the tool.

It will be appreciated that pipe proximity sensor 93 a could additionally or alternatively be added to a tool of the kind including the clamp 92 b. Equally a cover portion proximity sensor 93 b could be provided in a tool of the kind having a rolling belt 92 a; in this case the proximity sensor would not be operative to detect if the cover portion 91 was within the tool, but rather to detect whether or not the belt 92 a is engaged with the cover portion 91. The sensing means may operate through visible light, infra-red, or any other suitable means (e.g. an inductive sensor to determine the presence of a metal pipe in the proximity of the tool), or a pressure sensor to detect whether a rotating mechanism tool is engaged with the cover portion 91.

The sensing means may be provided with a light source to illuminate a relevant area (e.g. the retraction portion 91 a for the proximity sensor 93 b in the embodiment of FIG. 9B). It will also be appreciated that the sensing means may be cameras which relay a video to a screen for a human operator of the apparatus to use, or alternatively, in the case that the apparatus is robotic (i.e. predominately automated), the sensing means may be robot vision cameras which enable the system of the apparatus to accurately operate; the operation steps of the apparatus will be detailed later.

It will also be appreciated that in the case that the tool comprises a plurality of arms and engaging members (e.g. clamps or rotating mechanisms), there may be a plurality of sensing means connected to respective engaging members, or alternatively not all engaging members may be provided with a sensing means (e.g. just one sensing means may be provided). Each engaging member may be adapted to engage the cover portion of the cap.

The operation steps of the two tool embodiments will now be described with reference to FIGS. 10A to 11C. These examples will describe the unfurling of the cover portion and mounting the cap to the elongate member; however it will be appreciated that for furling the cover portion and dismounting the cap, the steps are simply reversed. The use of the sensing means will not be described in these embodiments, but as discussed above they may assist with all of the operational steps of the tool. The apparatus may comprise a control unit adapted to transmit control instructions which cause the tool to perform one or more actions, and one or more of the operational steps of the tool may be performed in response to receiving the control instructions from the control unit.

FIGS. 10A to 10C show the steps taken for the operation of a tool having a rolling belt 102; these steps would equally apply to a tool incorporating any rotating mechanism. FIG. 10A shows the cap applied to the end of the elongate member 104, but with the cover portion 101 in the non-gripping (furled) configuration (i.e. gathered onto base portion 100). The tool-arms 103 are positioned to engage the rolling belt 102 with the cover portion 101. The rolling belt 102 then spins, and the tool-arms 103 move the rolling belt 102 parallel to the elongate member 104, as can be seen in FIG. 10B.

FIG. 10C shows the cover portion 101 fully applied to the end of the elongate member 104, such that the retraction portion 101 a is visible. The tool-arms 103 can then be extended in a direction away from the elongate member 104/cap, and the operation of the tool is then complete. The tool-arms do not need to fully extend (see for example FIG. 7) away from the cap at this stage, so long as there is sufficient clearance between the tool-arms and the cap (i.e. so that the engaging member of the tool does not contact the base portion 100 when the apparatus is withdrawing from the mounted cap).

The apparatus of FIGS. 10A-10C may comprise a control unit adapted to transmit control instructions to the tool, drive mechanism, and/or gripping mechanism, and one or more of the operational steps of the apparatus may be performed in response to receiving the control instructions from the control unit.

FIGS. 11A to 11C show the operational steps of a tool having a clamp 112. The other reference numerals in FIGS. 11A to 11C correspond to those of FIGS. 10A to 10C, but 10 higher. FIG. 11A shows the clamp 112 engaged with the retraction portion 111 a of the cover portion 111, so the tool is ready to unfurl the cover portion 111 onto the end of the elongate member 114. The operational steps of the clamp 112 tool then correspond to the steps of the rolling belt 102 tool, the difference being that the clamp 112 moves with (i.e. rather than spins) the cover portion 111 to unfurl the cover portion 111; once the cover portion 111 has been fully unfurled by the clamp 112, the clamp 112 disengages with the retraction portion 111 a.

The apparatus of FIGS. 11A to 11C may comprise a control unit adapted to transmit control instructions to the tool, drive mechanism, and/or gripping mechanism, and one or more of the operational steps of the apparatus may be performed in response to receiving control instructions from the control unit.

The operation of the whole apparatus, in the red zone, will be described with reference to FIGS. 12A-12F. In this example an embodiment of the apparatus is shown with a tool having a rolling belt, a mechanical arm, and crescent gripping members; it will be appreciated that the operation of the apparatus is much the same for other tool types, drive mechanisms, and gripping mechanisms. Further, FIGS. 12A to 12F show the apparatus removing the cap, which is applied (i.e. in the gripping configuration) to the end of a drill pipe (elongate member), from the end of the drill pipe; for applying the cap to the elongate member the steps would be reversed accordingly. The apparatus may comprise a control unit adapted to transmit control instructions to the tool, drive mechanism, and/or gripping mechanism, and one or more of the operational steps of the apparatus may be performed in response to receiving control instructions from the control unit.

FIG. 12A shows the apparatus as it approaches drill pipe 120, onto which a protective cap is applied; the cover portion 126, comprising retraction portion 126 a is fully unfurled. The tool-arms 122 of the apparatus are holding the rolling belts 123 in an ‘open’ position (i.e. fully away from a central axis of the gripping mechanism 121. The drill pipe 120 and apparatus are in the red zone area demarked by red zone line 127. The apparatus, assisted by sensing means 123 a, centres the rolling belts 123 and tool-arms 122 of the tool, as well as the gripping mechanism 121, on the cap using arm 124. The arm 124 then moves the apparatus such that the base platform 121 b engages the base of the hard base portion 125. The crescent gripping members 121 a are then driven by an actuator to radially converge and engage the recess 125 a of the base portion 125.

FIG. 12B shows the gripping mechanism 121 engaged with the base portion 125 and, as described previously, the tool-arms 122 move the rolling belts to the tip of the cover portion 126.

The rolling belts 123 then operate to furl the cover portion 126; the tool-arms 122 move the rolling belts as required (parallel to the pipe 120 and towards the end of the pipe 120).

With the cover portion 126 fully gathered and situated over the hard base portion 125, the rolling belts 123 cease operation, and the tool-arms 122 extend the rolling belts 123 back to the ‘open’ position, as shown in FIG. 12C.

The arm 124 then withdraws the cap from the drill pipe 120, as shown in FIG. 12D. The insert portion 128 of the cap, which was engaged with the end of the drill pipe 120 is visible from this view. FIG. 12E shows the apparatus moving the cap way from the drill pipe 120 and out of the red zone area. In this embodiment the arm 124 controls at least 5 degrees of freedom. Firstly, the arm 124 controls the 3 position co-ordinates of the tool/gripping mechanism. Further, the tool/gripping mechanism may be tilted (e.g. relative to the ground), so the arm 124 also controls the pitch and roll of the tool/gripping mechanism. The arm 124 may further control a sixth degree of freedom, the yaw of the tool/gripping mechanism (i.e. the rotation of the tool/gripping mechanism about the central axis of the gripping mechanism); however, it will be appreciated that, particularly in the case of a radially symmetric tool/gripping mechanism, this is not essential. The apparatus may comprise a control unit adapted to transmit control instructions to the arm 124, and control of the arm 124 may be performed in response to receiving the control instructions from the control unit.

In an embodiment, the sensing means 123 a are robotic vision cameras, which may be used for a robotic arm to guide the cap to/from the pipe. Additionally or alternatively, the location of the end of the pipe 120 may be a known location (e.g. the arm may follow a predefined path, with the apparatus capable of making small corrections as required). The sensing means 123 a may be used to generate feedback which is transmitted to the control unit. The control unit may then use this feedback to generate or modify control instructions to be transmitted to the arm 124, thereby correcting the motion of the apparatus based on the feedback. In all automated embodiments, there may be a manual override which allows a human operator to remotely control the apparatus.

FIG. 12F shows the final stage of the cap removal, wherein the apparatus has removed the cap from the red zone (i.e. beyond the red zone line 127). This allows a person to manually collect the cap from the apparatus, although it will be appreciated that this stage too may be automated.

Whilst a significant benefit of this invention is that it enables operations in a red zone of a drilling rig to continue whilst protective caps are being removed from or applied to the ends of drill pipes, this invention is not limited to this. For example, this apparatus may be used by the manufacturer of elongate members, to apply the caps to the ends of the elongate members before transport or storage. 

1. An apparatus for applying and removing protective caps to and from the ends of elongate members, the protective cap having a hard base portion and a cover portion of flexible, resilient material, extending from the base portion and operative to cover a portion of an outer surface of the elongate member, the apparatus comprising: a gripping mechanism operative to grip the hard base portion of the protective cap; a drive mechanism, connected to the gripping mechanism, operative to move the protective cap to and from the end of the elongate member; and a tool configured to perform at least one of the operations of (i) unfurling the cover portion to secure it to the outer surface of the elongate member, (ii) furling the cover portion to detach it from the outer surface of the elongate member.
 2. An apparatus according to claim 1, wherein the tool comprises a clamp operative to grasp the cover portion to unfurl the cover portion when securing it to the outer surface of the elongate member and to furl the cover portion when detaching it from the outer surface of the elongate member.
 3. An apparatus according to claim 1, wherein the tool comprises at least one rotating mechanism operative to unfurl the cover portion when securing it to the outer surface of the elongate member and to furl the cover portion when detaching it from the outer surface of the elongate member.
 4. An apparatus according to claim 1, wherein the hard base portion of the protective cap comprises a recess, and the gripping mechanism comprises a plurality of gripping members which converge to slot into the recess.
 5. An apparatus according to claim 4, wherein the gripping members are crescent shaped.
 6. An apparatus according to claim 1, wherein the tool comprises a plurality of engaging members operative to engage the cover portion.
 7. An apparatus according to claim 6, wherein a centre of the gripping mechanism defines a central axis and the plurality of engaging members of the tool are spaced such that the tool is radially symmetric around the central axis.
 8. An apparatus according to claim 1, wherein the tool is provided with a sensing means operative to detect a distance between the tool and the elongate member.
 9. An apparatus according to claim 1, wherein the tool is provided with a sensing means operative to detect a distance between the tool and the cover portion.
 10. An apparatus according to claim 1, wherein the gripping mechanism is provided with a sensing means operative to detect a distance between the gripping mechanism and the hard base portion of the protective cap.
 11. (canceled)
 12. A method of applying a protective cap to the end of an elongate member using a protective cap application apparatus, the protective cap having a hard base portion and a cover portion of flexible, resilient material, extending from the base portion and operative to cover a portion of an outer surface of the elongate member, the protective cap application apparatus comprising: a gripping mechanism operative to grip the hard base portion of the protective cap; a drive mechanism, connected to the gripping mechanism, operative to move the protective cap to and from the end of the elongate member; and a tool configured to unfurl the cover portion to secure it to the outer surface of the elongate member; and the method comprising: using the gripping mechanism to grip the hard base portion of the protective cap; using the drive mechanism to move the protective cap to the end of the elongate member; and using the tool to unfurl the cover portion to secure it to the outer surface of the elongate member.
 13. A method of removing a protective cap from the end of an elongate member using a protective cap removal, the protective cap having a hard base portion and a cover portion of flexible, resilient material, extending from the base portion and operative to cover a portion of an outer surface of the elongate member, the protective cap removal apparatus comprising: a gripping mechanism operative to grip the hard base portion of the protective cap; a drive mechanism, connected to the gripping mechanism, operative to move the protective cap to and from the end of the elongate member; and a tool configured to furl the cover portion to detach it from the outer surface of the elongate member; the method comprising: using the tool to disengage the cover portion from the outer surface of the elongate member, while gripping mechanism grips the hard base portion of the protective cap; and using the drive mechanism to remove the protective cap from the end of the elongate member. 